Re: [PATCH v12 3/6] PCI: mediatek: Add new method to get irq number

From: Chuanjia Liu
Date: Thu Sep 02 2021 - 05:28:55 EST


On Tue, 2021-08-31 at 13:30 -0500, Bjorn Helgaas wrote:
> On Mon, Aug 23, 2021 at 11:27:57AM +0800, Chuanjia Liu wrote:
> > Use platform_get_irq_byname() to get the irq number
> > if the property of "interrupt-names" is defined.
>
> From patch 1/6, I have the impression that this patch is part of
> fixing an MSI issue. If so, this commit log should mention that as
> well.

Hi ,Bjorn
Yes,I will change the commit message as follow

In order to parse the new dts format that conforms to the hardware
design and fixes the MSI issue,add
platform_get_irq_byname_optional to get the irq number.

>
> > Signed-off-by: Chuanjia Liu <chuanjia.liu@xxxxxxxxxxxx>
> > Acked-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
> > ---
> > drivers/pci/controller/pcie-mediatek.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/pcie-mediatek.c
> > b/drivers/pci/controller/pcie-mediatek.c
> > index 4296d9e04240..19e35ac62d43 100644
> > --- a/drivers/pci/controller/pcie-mediatek.c
> > +++ b/drivers/pci/controller/pcie-mediatek.c
> > @@ -654,7 +654,11 @@ static int mtk_pcie_setup_irq(struct
> > mtk_pcie_port *port,
> > return err;
> > }
> >
> > - port->irq = platform_get_irq(pdev, port->slot);
> > + if (of_find_property(dev->of_node, "interrupt-names", NULL))
> > + port->irq = platform_get_irq_byname(pdev, "pcie_irq");
> > + else
> > + port->irq = platform_get_irq(pdev, port->slot);
>
> This would be the only instance of this pattern, where we look for a
> property and use the result to decide how to look for the IRQ.
>
> dw_pcie_host_init() does something like this:
>
> port->irq = platform_get_irq_byname_optional(pdev, "pcie_irq");
> if (port->irq < 0) {
> port->irq = platform_get_irq(pdev, port->slot);
> if (port->irq < 0)
> return port->irq;
> }
>
> Would that work for you? If not, the commit log should explain why
> you can't use the standard pattern.
>
> If you do things differently than other drivers, it makes things
> harder to review and slows things down. If you *have* to do
> something
> differently and it adds real value to be different, that's fine. But
> we should avoid unnecessary differences.

Thanks for your advice,it is very helpful to me, I will use standard
pattern to avoid unnecessary differences

Thanks again!
Chuanjia

>
> > if (port->irq < 0)
> > return port->irq;
> >
> > --
> > 2.18.0
> >